Re: proposal to change acosh



Raymond Toy wrote on 11/30/2005 12:08:07 PM:

> It would be nice if we could use Lisp conditions for this instead just
> plain ignore-errors.  I think every Lisp we support has this with the
> possible exception of gcl.

I agree. I've never messed with Lisp conditions.  Maybe the code
is organized in a way that would make a clear path for a knowledgeable
person to do this.

> Is there a reason we shouldn't checkin your work to maxima?  Or at
> least on a branch?  It would make it easier for me, at least, to
> contribute to your work.

No, I think it would be OK to check it in. If somebody would do that
for me, that would be great.  One thing that needs to be fixed already:

(setf (gethash '%sec cl-double-float-op) #'(lambda (x) (let ((y 
(ignore-errors (/ 1 (cl:cos x)))))
                                                         (if y y 
(domain-error x 'sec)))))

was

(setf (gethash '%sec cl-double-float-op) #'(lambda (x) (let ((y 
(ignore-errors (/ 1 (cl:cos x)))))
                                                         (if y (first y) 
(domain-error x 'sec)))))

And etc for the other functions. I flubbed when I changed from errset to 
ignore-errors.
 
>     Barton>    (1)  revise atan2, log, and exp so that these functions
>     Barton>         evaluate similarly to the way the other trig
>     Barton>         functions evaluate.
> 
> What does this mean?  You mean log(x+%i*y) will automatically evaluate
> when x and/or y are floats/bfloats?  If so, then yes, I agree.

Yes, this is what I meant --- these functions should use the same
mechanism for floating point evaluation as do the new trig functions.